Memória fisiológica a partir do estresse hídrico em Sorghum bicolor (L.) Moench com expressão da aquaporina PIP2;5
Carregando...
Arquivos
Data
2022-02-22
Autores
Pegorin, Priscila
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A deficiência hídrica provoca alterações fisiológicas, bioquímicas e estruturais. Respostas fisiológicas ocorrem após sinalização do déficit hídrico e promovem nas plantas a capacidade de armazenar informações geradas a partir do estímulo, iniciando o processo de memória fisiológica. Nossa hipótese é que a deficiência hídrica severa progressiva (DHSP), por ser recorrente, imprima memória fisiológica nos processos de reidratação, em especial no segundo evento, atrelada a expressão diminuída da PIP2;5 no período de estresse hídrico e superexpressão no momento da reidratação. Este estudo teve como objetivo avaliar respostas que caracterizam a memória fisiológica em Sorghum bicolor (L.) Moench a partir da deficiência hídrica severa progressiva (DHSP) com ênfase no processo de reidratação, analisando a relação com a aquaporina PIP2;5. As plantas foram separadas em dois grupos: controle e deficiência hídrica severa progressiva, cujo último tratamento foi submetido a dois eventos de restrição hídrica, seguidas de reidratações. Os dados de trocas gasosas, fluorescência da clorofila a, conteúdo relativo de água (CRA) e potenciais hídricos foliares e do solo (Ψw MPa), condutividade hidráulica foliar (Kplanta), atividade da enzima POD, nível de peroxidação lipídica, conteúdo de H2O2 e a expressão do gene PIP2;5 foram analisados. Os resultados demonstraram que o segundo evento de deficiência hídrica e reidratação promoveu respostas fisiológicas que indicam aumento da tolerância à restrição hídrica. O CRA, Ψw foliar e E, gs, indicam estratégias na economia do uso da água, evidenciando a memória de deficiência hídrica, bem como a aquaporina PIP2;5 que apresentou redução da sua expressão no período de seca, seguida de superexpressão assim que a reidratação foi aplicada, auxiliando nas relações hídricas da planta e no crescimento.
Water deficiency causes physiological, biochemical and structural changes. Physiological responses occur after water deficit signaling and promote in plants the ability to store information generated from the stimulus, initiating the physiological memory process. Our hypothesis is that the severe progressive water deficit (DHSP), as it is recurrent, imprints physiological memory in the rehydration processes, especially in the second event, linked to the decreased expression of PIP2;5 in the period of water stress and overexpression at the time of rehydration. This study aimed to evaluate responses that characterize physiological memory in Sorghum bicolor (L.) Moench from severe progressive water deficit (DHSP) with emphasis on the rehydration process, analyzing the relationship with aquaporin PIP2;5. The plants were divided into two groups: control and severe progressive water deficit, whose last treatment was submitted to two water restriction events, followed by rehydration. Gas exchange data, chlorophyll a fluorescence, relative water content (CRA) and soil and leaf water potentials (Ψw MPa), leaf hydraulic conductivity (Kplanta), POD enzyme activity, lipid peroxidation level, H2O2 content and PIP2;5 gene expression were analyzed. The results showed that the second event of water deficiency and rehydration promoted physiological responses that indicate increased tolerance to water restriction. The CRA, foliar Ψw and E, gs, indicate strategies in the economy of water use, evidencing the memory of water deficit, as well as the aquaporin PIP2;5 which showed a reduction in its expression in the dry period, followed by overexpression as soon as the rehydration was applied, helping the plant's water relations and growth.
Water deficiency causes physiological, biochemical and structural changes. Physiological responses occur after water deficit signaling and promote in plants the ability to store information generated from the stimulus, initiating the physiological memory process. Our hypothesis is that the severe progressive water deficit (DHSP), as it is recurrent, imprints physiological memory in the rehydration processes, especially in the second event, linked to the decreased expression of PIP2;5 in the period of water stress and overexpression at the time of rehydration. This study aimed to evaluate responses that characterize physiological memory in Sorghum bicolor (L.) Moench from severe progressive water deficit (DHSP) with emphasis on the rehydration process, analyzing the relationship with aquaporin PIP2;5. The plants were divided into two groups: control and severe progressive water deficit, whose last treatment was submitted to two water restriction events, followed by rehydration. Gas exchange data, chlorophyll a fluorescence, relative water content (CRA) and soil and leaf water potentials (Ψw MPa), leaf hydraulic conductivity (Kplanta), POD enzyme activity, lipid peroxidation level, H2O2 content and PIP2;5 gene expression were analyzed. The results showed that the second event of water deficiency and rehydration promoted physiological responses that indicate increased tolerance to water restriction. The CRA, foliar Ψw and E, gs, indicate strategies in the economy of water use, evidencing the memory of water deficit, as well as the aquaporin PIP2;5 which showed a reduction in its expression in the dry period, followed by overexpression as soon as the rehydration was applied, helping the plant's water relations and growth.
Descrição
Palavras-chave
Aprendizagem, Seca, Sinal de estresse, Resposta fisiológica, Recuperação fisiológica, Learning, Dry, Stress sign, Physiological response, Physiological recovery